Timothy gilbert



UNITED STATES PATENT OFFICE.

v TIMOTHY GILBERT, OF BOSTON, MASSACHUSETTS.

METALLIC FRAME FOR PIANOFORTES.

Specification of Letters Patent No. 5,202, dated July 24, 184.-?.

To all whom t may concern Be it known that I, TIMOTHY GILBERT, ofBoston, in the county of Suffolk and State of yl\/Iassacliusetts, haveinvent-ed a new and useful Improvement in Metallic Frames for GrandPianofortes; and I do hereby declare that the same is fully describedand represented in the following specification and accompanyingdrawings, letters, figures, and references thereof.

Of said drawings Figure l represents a top view of my improved cast ironframes for pianofortes. Fig. 2 is a longitudinal and vertical sectiontaken through a Z) of Fig. 1. Fig. 3 is a transverse and verticalsection taken through c, cl, Fig. l.

A denotes the main part of the frame and B, B, B, the longitudinalstrengthening bars -made and combined together in the usual form andmanner.

My improvement consists in applying to said frame and longitudinal bars,transverse or cross bars C, C, C, which I cast in connection with thelong bars, and main part of the frame. I apply beneath the frame, andtransversely near the head of it, a deep cross bar D, which I also castto the frame, and to the longitudinal bars B, B, B. Both thelongitudinal and transverse bars B, B, B, and C, C, C, should in generalbe elevated somewhat above the strings F, F, &c., which extend from thecurved part a, to the head piece b of the frame as seen in the drawings.The hitch pins of the strings are inserted in the curved part a, whilethe straining pins are arranged in the head plate The cast iron framesheretofore made having been constructed with longitudinal bars only, inorder to counteract the strain on the curved plate and screw or headplate of the frame, such bars operated only as struts in the directionof their lengths. They do not prevent to any material eX- tent, thecurved part of the frame from springing inward or from twisting down towhich it is liable from the manner in which the strain of the strings isbrought to bear upon it. The cross bars C, C, C, operate to prevent notonly the bending inward of the curved part of the frame, but the torsionstrain upon the said curved part.

What I claim is- The combination of the cross bars, with thelongitudinal bars, and straight and curved sides of the main frame, inthe manner as described, whereby the said cross bars, serve as supportsto the same, in order to prevent their springing out of place,laterally, as specified, thus making the frame itself do all the work ofsupporting the strains of the strings, and avoiding theemployment of theusual bolts, and wooden framework (other than the case or frame of theinstrument) to which the iron frame is usually confined, the cross barbeneath the frame, serving the purpose of an important support to theheadv of the frame, and also to t-he sounding board, the end of which isto be attached directly or indirectly to it.

In testimony whereof I have hereto set my signature this first day'ofFebruary, A. D.

TIMOTHY GILBERT. IVitnesses R. H. EDDY, S. W. WALDRON, J r.

